This invention relates generally to hose fittings and, more particularly, to a fitting for flexible hoses which enables the hose to be snap-connected to a hose-receiving nipple, which securely retains the hose on the nipple under conditions of vibration and pressure development in the hose, and which enables the hose to be released from the nipple when desired by a relatively simple manipulation.
Flexible hoses are used in a variety of applications to conduct fluids between components. In the automotive field, for example, most modern day vehicles include gasoline engines that are equipped with anti-pollution equipment. Typically, this equipment comprises several interacting parts that are connected together, or to parts of the engine such as the carbuerator, distributor and the like, by small diameter flexible rubber hoses. It is important for the proper operation of the anti-pollution equipment and, in some cases, for the proper operation of the engine itself, that these hoses maintain their intended connections at all times during the use of the vehicle. It is equally important, however, that these hoses be readily removable from their connections when repairs to the anti-pollution equipment and/or the engine are to be made.
Prior arrangements for connecting flexible hoses to the operative parts of the anti-pollution equipment have typically involved design trade-offs between the retention and removal properties of the connection. In most prior designs, the part that receives the hose is equipped with a nipple which is dimensioned to fit within the internal channel of the hose. In some designs, a fastener, such as a screw-tightenable band or ring-shaped spring clip, is used to squeeze the hose against the inserted nipple and thereby to hold the hose in place. These designs are usually adequate in retaining the hose on the nipple in spite of engine vibration and high pressure development in the hose, but are disadvantaged because of the inconvenience involved in loosening or repositioning the fastener when the hose is to be removed from the nipple.
In other designs, no fastener is used, but the nipple is provided with peripheral ridges or barbs which grip the internal channel defining wall of the hose when the nipple is inserted. With the latter designs, the hose is usually easy to remove simply by pulling it from the nipple. However, hose manufacturing tolerances are such that the internal channel of the hose is sometimes too large for the nipple in which case the ridges or barbs are ineffective in gripping the hose. Also, through the process of removing and reinserting the hose on the nipple, the hose can stretch or split or material can be pulled from the internal wall of the hose to loosen the connection. Additionally, the hoses often become brittle with age, making it difficult for the nipple ridges or barbs to bite or grip the hose. As a result, the latter designs have experienced problems with the hose being vibrated or blown from the nipple.
There thus exists a need in the automotive field and in other fields utilizing flexible, fluid conducting hoses, for improved hose fittings that provide both secure retention and ready releasability when desired.